@article{10_37236_2383,
     author = {Aida Abiad and Willem H Haemers},
     title = {Cospectral graphs and regular orthogonal matrices of level 2},
     journal = {The electronic journal of combinatorics},
     year = {2012},
     volume = {19},
     number = {3},
     doi = {10.37236/2383},
     zbl = {1253.05092},
     url = {http://geodesic.mathdoc.fr/articles/10.37236/2383/}
}